Purpose: This systematic review aimed to investigate the accuracy of intraoral scan (IOS) impressions of implant-supported restorations in in vivo studies.
Methods: A systematic electronic search and review of studies on the accuracy of IOS implant impressions were conducted to analyze the peer-reviewed literature published between 1989 and August 2023. The bias analysis was performed by two reviewers. Data on the study characteristics, accuracy outcomes, and related variables were extracted. A meta-analysis of randomized control trials was performed to investigate the impact of IOS on peri-implant crestal bone loss and the time involved in the impression procedure.
Results: Ten in vivo studies were included in this systematic review for final analysis. Six studies investigated the trueness of IOS impressions, but did not reach the same conclusions. One study assessed the precision of IOS impressions for a single implant. Four clinical studies examined the accuracy of IOS implant impressions with a follow-up of 1-2 years. In full arches, IOS impression procedure needed significantly less time than conventional one (mean difference for procedure time was 8.59 min [6.78, 10.40 min], P < 0.001), prosthetic survival rate was 100%, and marginal bone levels of all participants could be stably maintained (mean difference in marginal bone loss at 12 months was 0.03 mm [-0.08, 0.14 mm], P = 0.55).
Conclusions: The accuracy of IOS impressions of implant-supported restorations varied greatly depending on the scanning strategy. The trueness and precision of IOS in the partial and complete arches remain unclear and require further assessment. Based on follow-up clinical studies, IOS impressions were accurate in clinical practice. However, these results should be interpreted with caution, as some evidences are obtained from the same research group.
Purpose: A high transfer accuracy of the intraoral implant position to a model is required, to manufacture implant-supported restorations. However, clinically relevant deviations persist between the intraoral implant position and the model obtained, even for the benchmark conventional custom implant impressions with polyether. Thus, new approaches using 3-D printed impression trays may increase the transfer accuracy of implant impressions. The ability to adjust parameters such as the thickness of the layers and the influence of the openings in the impression tray could potentially affect accuracy.
Methods: Four different types of impression trays (n = 10 for each group) for the conventional impression technique were investigated: conventional custom impression tray, customized foil tray, chairside 3-D printed impression tray with the SHERA system, and the Primeprint system using an implant master model with four implants in the posterior region and a reference cube. After plaster model casting, all models were measured using a coordinate measuring machine, and the deviation from the reference dataset was determined. A statistical ANOVA analysis was performed (p < 0.05).
Results: Chairside 3-D printed impression trays showed the best results, followed by conventional custom impression trays. Implant impressions obtained using a customized foil tray exhibited the lowest accuracy. Statistically significant differences were observed between 3-D printed impression trays and conventional custom impression and customized foil trays (p < 0.05). Whereas, the implant position did not have any significant influence on accuracy (p > 0.05).
Conclusions: Chairside 3-D printed impression trays significantly increase the transfer accuracy for implant impression taking.
Purpose: The aim of this study is to examine and compare the accuracy of implant placement using implant positional guide and freehand.
Methods: 48 implants were placed in patients with single tooth loss with implant positional guide and freehand, respectively. The accuracy of implant placement was assessed by comparing the actual and planned position, including four parameters: coronal deviation, apical deviation, angular deviation, and vertical deviation.
Results: Comparing all the variables, it has been found that the implant positional guide is more accurate than the freehand. All parameters describing in the deviation were significantly lower in the implant positional guide group than the freehand.
Conclusions: The implant positional guide can act as a practicable tool for dental implant surgery. It is a promising technology that guarantees low cost and high precision in implant surgery. However, based on the restricted evidence from clinical studies, longer follow-up periods, larger population studies, and standardized experimental studies are required. Trial registration CHICTR, ChiCTR2300071024. Registered 28 April 2023-CHICTR, ChiCTR2300071024. Registered 28 April 2023-Retrospectively registered, https://www.chictr.org.cn/showproj.html?proj=195424 .
Purpose: To investigate the influence of cantilever prosthetic arm on the marginal bone loss (MBL) over time around dental implants supporting short fixed partial dentures (FPDs), in a record-based retrospective study.
Methods: All cases of 3-unit implant-supported FPDs, supported by 2-3 implants, from the database of cases treated at one specialist clinic were considered for inclusion. Only implants with a minimum of 36 months of radiological follow-up were considered. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built.
Results: One-hundred-thirty-nine patients (64 men, 75 women) with 164 3-unit implant-supported FPDs (333 implants supporting non-cantilevered FPDs, 94 supporting cantilevered FPDs) were included in the study. The patients were followed up clinically and radiographically for a mean of 154.1 ± 78.0 (min-max, 37.3-364.6) and 132.9 ± 77.3 months (min-max, 36.8-329.9), respectively. The total number of marginal bone level double measurements (mesial and distal sides of each implant) was 2909. FPDs with cantilever presented an estimated greater MBL over time compared to FPDs without cantilever. Bruxism, sex (women), implant (modified) surface, and (poor) bone quality were also associated with higher MBL over time.
Conclusions: The use of a cantilever extension is suggested to negatively affect the bone marginal level over time around implants supporting 3-unit FPDs. Due to the small difference of the estimated MBL over long periods of follow-up between the groups, it is a matter of debate if the observed negative effect may be of clinical significance.
Purpose: Post-interventional hemorrhage can result in serious complications, especially in patients with hemostatic disorders. Identification of safe and efficient local hemostatic agents is important, particularly in the context of an ageing society and the emergence of new oral anticoagulants. The aim of this in vitro study was to investigate the potential of silk fibroin membranes coated with the inorganic polymer polyphosphate (polyP) as a novel hemostatic device in oral surgery.
Methods: Cocoons of the silkworm Bombyx mori were degummed and dissolved. Varying amounts of long-chain polyP (2-2000 µg/mm2) were adsorbed to the surface of silk fibroin membranes. Analysis of the procoagulant effect of polyP-coated silk membranes was performed using real-time thrombin generation assays in human plasma. Increasing concentrations of polyP (0.15-500 µg/ml) served as a positive control, while uncoated silk fibroin membranes were used as negative control.
Results: PolyP-coated silk fibroin membranes triggered coagulation when compared to plasma samples and pure silk fibroin membranes. A polyP-dose-dependent effect of thrombin generation could be found with a maximum (ETP = 1525.7 nM⋅min, peak thrombin = 310.1 nM, time to peak = 9.8 min, lag time = 7.6 min.) at 200 µg/mm2 of polymer loading on the silk fibroin membrane surface.
Conclusions: In this study, it was demonstrated that silk fibroin membranes coated with polyP have the potential to act as a promising novel hemostatic device.
Purpose: Implant-supported immediately loaded fixed full-arch rehabilitation via All-on-four treatment yields good long-term results for both the maxilla and the mandible. However, the risk factors affecting long-term implant survival are unknown, and the long-term prognosis of All-on-four concept procedures in Japanese individuals has not been elucidated. We aimed to determine the cumulative implant survival rate after 3-17-year follow-up and identify the associated risk factors.
Methods: We analysed 561 cases (307 maxillae, 254 mandibles) with 2364 implants (1324 maxillae, 1040 mandibles) that received All-on-four treatment. We investigated the cumulative implant- and patient-level survival rates and various risk factors for implant failure. Statistical analysis was performed using the log-rank test for differences in Kaplan-Meier curves, univariate analysis using the Chi-square test, and multivariate analysis for risk factors affecting the survival rate.
Results: The cumulative survival rate was 94.4% by patient level and 97.4% by implant level for the maxilla, and 96.7% by patient level and 98.9% by implant for the mandible, with up to 17 years of follow-up. The maxillary survival rate at the implant level was significantly lower (p < 0.05). Furthermore, the maxillary survival rate within 24 months was significantly lower at the implant level (p < 0.01). Multivariate analysis revealed that the maxilla was the most significant risk factor (p < 0.01).
Conclusions: All-on-four treatment yielded high long-term survival rates in Japanese patients. However, the maxilla showed a significantly lower cumulative survival rate than the mandible, while early failure was significantly higher. Furthermore, the maxilla was a significant risk factor influencing the survival rate.
Purpose: To evaluate the effectiveness of using Densah burs for lifting the maxillary sinus membrane in cases with an oblique sinus floor with a residual bone height of 4-7 mm.
Methods: The study was conducted on 16 patients, comprising 9 males and 7 females, aged 25-60 years, split into two groups of 8 each: group I with a residual bone height of 4-5.5 mm below the sinus floor and group II with a residual bone height of 5.5-7 mm. Exclusion criteria included smokers, presence of systemic or metabolic conditions that contraindicate implant placement and a local sinus pathology. The study involved the use of Densah burs, using the osseodensification concept to elevate the sinus floor, along with simultaneous dental implant placement. The integrity of the sinus membrane was verified via clinical examination and a confirmatory cone beam computed tomography scan.
Results: The study revealed that out of the 16 cases, one case had a sinus membrane perforation, confirmed clinically at the time of the operation. The study achieved a mean lift of 4.42 mm and a mean final seating torque of 35.5 N/cm. At the 1-year follow-up, all cases showed clinical success, with no signs of sinus pathology or complications.
Conclusions: In cases with oblique sinus floors and a residual bone height of 4-7 mm in moderately atrophic posterior maxilla, the osseodensification concept proved to be a safe and effective method for performing sinus lift procedures with simultaneous implantation.
Purpose: The aim of this study is to compare dental implant placement accuracy of three surgical guide fabrication methods: single (SCT) and double computed tomography (DCT), and a newly developed modified SCT (MSCT) scan method.
Methods: A total of 183 cases (183 surgical guides, and 485 implants) of static-guide-assisted implant placement surgery using the SCT, DCT, or MSCT methods in a dental clinic were included in the study. Three-dimensional (3D) deviations (mm) at the entry and tip of the implant body between preoperative simulation and actual placement were measured as surrogate endpoints of implant placement accuracy. The following survey details were collected from medical records and CT data: sex, age at implant placement surgery, surgical guide fabrication method, number of remaining teeth, implant length, implant location, alveolar bone quality, and bone surface inclination at implant placement site in preoperative simulation, etc. Risk factors for reducing implant placement accuracy were investigated using generalized estimating equations.
Results: The SCT and DCT methods (odds ratios [ORs] vs. MSCT method: 1.438, 1.178, respectively), posterior location (OR: 1.114), bone surface buccolingual inclination (OR: 0.997), and age at implant placement surgery (OR: 0.995) were significant risk factors for larger 3D deviation at the entry; the SCT (OR: 1.361) and DCT methods (OR: 1.418), posterior location (OR: 1.190), implant length (OR: 1.051), and age at implant placement surgery (OR: 0.995) were significant risk factors for larger 3D deviation at the tip of the implant body.
Conclusions: Implant placement accuracy was better using the MSCT method compared to the SCT and DCT methods.
Background/aim: The aim of this study was to analyze a population of patients who had suffered from traumatic dental injuries (TDIs) by using different patient-, trauma- and treatment-related parameters.
Material and methods: All dental records of patients ≥ 3 years old who had presented at the dental emergency service between Jan 1, 2009 and Dec 31, 2016 for the treatment of dental trauma were analyzed. A total of 2758 patients were invited for a recall examination at the Department for Dental Surgery and Implantology, ZZMK Carolinum, Goethe University Frankfurt, Germany; of these, 269 patients attended their recall appointments.
Results: The enrolled patient population consisted of 1718 males and 1040 females, with a mean age of 19.63 years (median 12.00 ± 17.354 years). A total of 4909 injured teeth were assessed, with a mean of 1.78 injured teeth per patient (median 2.00 ± 1.279). Males were found to be more frequently affected by TDIs compared to females (1.65:1). The majority of these injuries occurred in the first two decades of life (66.1%; n = 1824). The majority of the patients presented for initial treatment within 24 h of their accident (95.7%). The most frequent TDIs were isolated luxation injuries 49.4% (n = 2426) and isolated crown fractures 30% (n = 1472). Combination injuries were diagnosed in 20.6% of the cases (n = 1011).
Conclusions: Based on the findings of the present analysis, it can be concluded that males were more frequently affected by TDIs than females. Most patients had suffered from TDI before they had turned 10 years of age. Overall, the enamel-dentin fracture was found to be the most frequent injury, followed by concussions and lateral luxations.